Association of Baseline Factors With Glycemic Outcomes in GRADE: A Comparative Effectiveness Randomized Clinical Trial

OBJECTIVE

To describe the individual and joint associations of baseline factors with glycemia, and also with differential effectiveness of medications added to metformin.

RESEARCH DESIGN AND METHODS

Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE) participants (with type 2 diabetes diagnosed for <10 years, on metformin, and with HbA1c 6.8-8.5%; N = 5,047) were randomly assigned to a basal insulin (glargine), sulfonylurea (glimepiride), glucagon-like peptide 1 agonist (liraglutide), or dipeptidyl peptidase 4 inhibitor (sitagliptin). The glycemic outcome was HbA1c ≥7.0%, subsequently confirmed. Univariate and multivariate regression and classification and regression tree (CART) analyses were used to assess the association of baseline factors with the glycemic outcome at years 1 and 4.

RESULTS

In univariate analyses at baseline, younger age (<58 years), Hispanic ethnicity, higher HbA1c, fasting glucose, and triglyceride levels, lower insulin secretion, and relatively greater insulin resistance were associated with the glycemic outcome at years 1 and/or 4. No factors were associated with differential effectiveness of the medications by year 4. In multivariate analyses, treatment group, younger age, and higher baseline HbA1c and fasting glucose were jointly associated with the glycemic outcome by year 4. The superiority of glargine and liraglutide at year 4 persisted after multiple baseline factors were controlled for. CART analyses indicated that failure to maintain HbA1c <7% by year 4 was more likely for younger participants and those with baseline HbA1c ≥7.4%.

CONCLUSIONS

Several baseline factors were associated with the glycemic outcome but not with differential effectiveness of the four medications. Failure to maintain HbA1c <7% was largely driven by younger age and higher HbA1c at baseline. Factors that predict earlier glycemic deterioration could help in targeting patients for more aggressive management.

The Use of Rescue Insulin in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE)

OBJECTIVE

To describe rescue insulin use and associated factors in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE).

RESEARCH DESIGN AND METHODS

GRADE participants (type 2 diabetes duration <10 years, baseline A1C 6.8%-8.5% on metformin monotherapy, N = 5,047) were randomly assigned to insulin glargine U-100, glimepiride, liraglutide, or sitagliptin and followed quarterly for a mean of 5 years. Rescue insulin (glargine or aspart) was to be started within 6 weeks of A1C >7.5%, confirmed. Reasons for delaying rescue insulin were reported by staff-completed survey.

RESULTS

Nearly one-half of GRADE participants (N = 2,387 [47.3%]) met the threshold for rescue insulin. Among participants assigned to glimepiride, liraglutide, or sitagliptin, rescue glargine was added by 69% (39% within 6 weeks). Rescue aspart was added by 44% of glargine-assigned participants (19% within 6 weeks) and by 30% of non-glargine-assigned participants (14% within 6 weeks). Higher A1C values were associated with adding rescue insulin. Intention to change health behaviors (diet/lifestyle, adherence to current treatment) and not wanting to take insulin were among the most common reasons reported for not adding rescue insulin within 6 weeks.

CONCLUSIONS

Proportionately, rescue glargine, when required, was more often used than rescue aspart, and higher A1C values were associated with greater rescue insulin use. Wanting to use noninsulin strategies to improve glycemia was commonly reported, although multiple factors likely contributed to not using rescue insulin. These findings highlight the persistent challenge of intensifying type 2 diabetes treatment with insulin, even in a clinical trial.

Neuropathic Pain With and Without Diabetic Peripheral Neuropathy in Type 1 Diabetes

OBJECTIVE

Diabetic peripheral neuropathy (DPN) is common; however, the features and burden of neuropathic pain (NP) in type 1 diabetes (T1D) are poorly understood. We evaluated the incidence of first occurrence, annual prevalence, remission, and risk factors for NP during long-term follow-up of participants with T1D.

RESEARCH DESIGN AND METHODS

The Michigan Neuropathy Screening Instrument (MNSI) was administered annually (1994-2020) for 1,324 participants in the Epidemiology of Diabetes Interventions and Complications (EDIC) study. NP with clinical signs of DPN (NP DPN+) was defined according to self-reported NP plus an examination score >2, while NP without clinical signs of DPN (NP DPN-) was defined according to self-reported NP and an examination score ≤2.

RESULTS

At EDIC year 1, median age for participants was 36 years (interquartile range 30, 41), diabetes duration 13 years (10, 18), and HbA1c 7.9% (7.2, 8.9). At year 26 (median diabetes duration 39 years), cumulative incidence of NP was 57%, regardless of concomitant clinical signs of DPN (36% NP DPN+ vs. 46% NP DPN-). NP prevalence was 20% at 26 years (11% NP DPN+ and 9% NP DPN-), suggesting frequent remission. Annualized remission rates were similar regardless of pain medication use. In addition to HbA1c, female sex was associated with NP DPN-.

CONCLUSIONS

NP incidence in T1D was high and frequently occurred in the absence of clinical signs of neuropathy, as assessed with the MNSI. Pain remission was not explained by pain medication use. Effective clinical strategies for identification and management are needed.

The NIDDK Diabetic Foot Consortium

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Diabetic Foot Consortium (DFC) was established in September 2018 by the NIDDK to build an organization to facilitate the highest quality of clinical research on diabetic foot ulcers (DFUs) that will answer clinically significant questions to improve DFU healing and prevent amputations. The initial focus of the DFC is to develop and validate biomarkers for DFUs that can be used in clinical care and research. The DFC consists of a data coordinating center (DCC) for operational oversight and statistical analysis, clinical sites for participant recruitment and evaluation, and biomarker analysis units (BAUs). The DFC is currently studying biomarkers to predict wound healing and recurrence and is collecting biosamples for future studies through a biorepository. The DFC plans to address the challenges of recruitment and eligibility criteria for DFU clinical trials by taking an approach of "No DFU Patient Goes Unstudied." In this platform approach, clinical history, DFU outcome, wound imaging, and biologic measurements from a large number of patients will be captured and the in-depth longitudinal data set will be analyzed to develop a computational-based DFU risk factor profile to facilitate scientifically sound clinical trial design. The DFC will expand its platform to include studies of the role of social determinants of health, such as food insecurity, housing instability, limited health literacy, and poor social support. The DFC is starting partnerships with the broad group of stakeholders in the wound care community.

On diabetic foot ulcer knowledge gaps, innovation, evaluation, prediction markers, and clinical needs

Diabetic foot ulcers (DFUs) remain a very prevalent and challenging complication of diabetes worldwide due to high morbidity, high risks of lower extremity amputation and associated mortality. Despite major advances in diabetes treatment in general, there is a paucity of FDA approved technologies and therapies to promote successful healing. Furthermore, accurate biomarkers to identify patients at risk of non-healing and monitor response-to-therapy are significantly lacking. To date, research has been slowed by a lack of coordinated efforts among basic scientists and clinical researchers and confounded by non-standardized heterogenous collection of biospecimen and patient associated data. Novel technologies, especially those in the single and 'multiomics' arena, are being used to advance the study of diabetic foot ulcers but require pragmatic study design to ensure broad adoption following validation. These high throughput analyses offer promise to investigate potential biomarkers across wound trajectories and may support information on wound healing and pathophysiology not previously well understood. Additionally, these biomarkers may be used at the point-of-care. In combination with national scalable research efforts, which seek to address the limitations and better inform clinical practice, coordinated and integrative insights may lead to improved limb salvage rates.

Physical Function in Middle-aged and Older Adults With Type 1 Diabetes: Long-term Follow-up of the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Study

OBJECTIVE

To describe the prevalence and clinical correlates of functional limitations in middle-aged and older adults with long-standing type 1 diabetes.

RESEARCH DESIGN AND METHODS

Functional limitations were assessed for 1,094 participants in the Epidemiology of Diabetes Interventions and Complications (EDIC) study, a multicenter, longitudinal, observational follow-up of participants with type 1 diabetes randomly assigned to intensive or conventional diabetes therapy during the Diabetes Control and Complications Trial (DCCT). The primary outcome measure was a score <10 on the Short Physical Performance Battery (SPPB). The secondary outcome, self-reported functional limitation, was assessed by written questionnaire. Logistic regression models were used to assess associations of both outcomes with demographic and clinical factors (glycemic and nonglycemic factors, micro- and macrovascular complications, DCCT cohort, and treatment assignment).

RESULTS

Participants were 53% male, with mean ± SD age 59.5 ± 6.8 years and diabetes duration 37.9 ± 4.9 years. The prevalence of SPPB score <10 was 21%. The prevalence of self-reported functional limitations was 48%. While DCCT treatment assignment was not associated with physical function outcomes measured ∼25 years after the end of the DCCT, the time-weighted mean DCCT/EDIC HbA1c was associated with both outcomes. Other clinical factors associated with both outcomes in multivariable analyses were BMI, general psychological distress, and cardiac autonomic neuropathy.

CONCLUSIONS

Almost half of the middle-aged and older adults with long-standing type 1 diabetes reported functional limitations, which were associated with higher HbA1c and BMI, general psychological distress, and cardiac autonomic neuropathy. Future research is needed to determine whether these findings are generalizable.

Diabetic Peripheral Neuropathy and Urological Complications in Type 1 Diabetes: Findings From the Epidemiology of Diabetes Interventions and Complications Study

OBJECTIVE

To evaluate associations between diabetic peripheral neuropathy (DPN) and urological complications in men and women with type 1 diabetes (T1D).

RESEARCH DESIGN AND METHODS

Measurements of DPN at Epidemiology of Diabetes Intervention and Complications (EDIC) years 1, 14, and 17 and urological complications at EDIC year 17 were examined in 635 men (mean age 51.6 years, diabetes duration 29.5 years) and 371 women (mean age 50.6 years, diabetes duration 29.8 years) enrolled in the Diabetes Control and Complications Trial (DCCT)/EDIC study. DPN was defined by symptoms, signs, and abnormal electrophysiology or by abnormal Michigan Neuropathy Screening Instrument (MNSI) examination or questionnaire scores.

RESULTS

Erectile dysfunction (ED) in combination with lower urinary tract symptoms (LUTS) was reported in 15% of men and female sexual dysfunction (FSD), LUTS, and urinary incontinence (UI) in 16% of women. Adjusted for age, drinking status, BMI, depression, DCCT/EDIC time-weighted mean HbA1c, microalbuminuria, hypertension, triglycerides, and statin medication use, the odds of reporting ED and LUTS versus no ED or LUTS at EDIC year 17 were 3.52 (95% CI 1.69, 7.31) times greater in men with confirmed DPN at EDIC year 13/14 compared to men without confirmed DPN. Compared to men without DPN, men with DPN based on abnormal MNSI examination or questionnaire scores had significantly higher odds of reporting ED and LUTS versus no ED or LUTS at EDIC year 17. There were no significant differences in DPN between women reporting both FSD and LUTS/UI compared with those without FSD or LUTS/UI at EDIC year 17.

CONCLUSIONS

In long-standing T1D, DPN is associated with the later development of urological complications in men.

The cross-sectional association of cognition with diabetic peripheral and autonomic neuropathy-The GRADE study

BACKGROUND

Studies examining whether measures of cognition are related to the presence of diabetic peripheral neuropathy (DPN) and/or cardiovascular autonomic neuropathy (CAN) are lacking, as are data regarding factors potentially explaining such associations.

METHODS

Participants were from the Glycemia Reduction Approaches in Diabetes Study (GRADE) that examined 5047 middle-aged people with type 2 diabetes of <10 years of known duration. Verbal learning and immediate and delayed recall (memory) were assessed with the Spanish English Verbal Learning Test; frontal executive function and processing speed with the Digit Symbol Substitution Test; and ability to concentrate and organize data with word and animal fluency tests. DPN was assessed with the Michigan Neuropathy Screening Instrument and CAN by indices of heart rate variability (standard deviation of normal beat to beat variation [SDNN] and root mean square of successive differences [RMSSD]).

RESULTS

DPN was significantly inversely related to measures of immediate recall and processing speed. The percent of cognitive variation explained by DPN was small. Tests of CAN had an inconsistent or absent association with measures of cognition. Higher waist circumference and urine albumin creatinine (UACR) levels were the strongest correlates in the relationship between DPN and cognitive impairment.

CONCLUSION

DPN, but not CAN, was cross-sectionally associated with lower performance in measures of cognition in people with type 2 diabetes of <10 years of known duration. Greater waist circumference and UACR were important variables in this association. The mechanisms underlying the cross-sectional association of DPN with cognitive impairment are unknown. Clinicaltrials.gov: NCT01794143.

Risk Factors for Diabetic Peripheral Neuropathy and Cardiovascular Autonomic Neuropathy in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) Study

The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study demonstrated that intensive glucose control reduced the risk of developing diabetic peripheral neuropathy (DPN) and cardiovascular autonomic neuropathy (CAN). We evaluated multiple risk factors and phenotypes associated with DPN and CAN in this large, well-characterized cohort of participants with type 1 diabetes, followed for >23 years. DPN was defined by symptoms, signs, and nerve conduction study abnormalities in ≥2 nerves; CAN was assessed using standardized cardiovascular reflex tests. Generalized estimating equation models assessed the association of DPN and CAN with individual risk factors measured repeatedly. During DCCT/EDIC, 33% of participants developed DPN and 44% CAN. Higher mean HbA_1c was the most significant risk factor for DPN, followed by older age, longer duration, greater height, macroalbuminuria, higher mean pulse rate, β-blocker use, and sustained albuminuria. The most significant risk factor for CAN was older age, followed by higher mean HbA_1c, sustained albuminuria, longer duration of type 1 diabetes, higher mean pulse rate, higher mean systolic blood pressure, β-blocker use, estimated glomerular filtration rate <60 mL/min/1.73 m², higher most recent pulse rate, and cigarette smoking. These findings identify risk factors and phenotypes of participants with diabetic neuropathy that can be used in the design of new interventional trials and for personalized approaches to neuropathy prevention.

Risk factors for orgasmic and concomitant erectile dysfunction in men with type 1 diabetes: a cross-sectional study

In this study, we sought to determine the burden and characteristics of orgasmic dysfunction (OD) and concomitant erectile dysfunction (ED) in men with type 1 diabetes (T1D) enrolled in the Epidemiology of Diabetes Interventions and Complications (EDIC) study. In 2010, we assessed orgasmic and erectile function using the International Index of Erectile Function (IIEF). Sociodemographic, clinical, and diabetes characteristics were compared by OD status (OD only, OD and ED, no ED or OD). Age-adjusted associations between risk factors and OD status were examined. OD and ED information was available from 563 men. Eighty-three men (14.7%) reported OD of whom 21 reported OD only and 62 reported OD and ED. Age-adjusted odds ratios demonstrated that men who reported OD only had higher odds of depression, low sexual desire, and decreased alcohol use compared with men reporting no dysfunction. Men with OD concomitant with ED had greater odds of elevated hemoglobin A1C, peripheral and autonomic neuropathy, and nephropathy. Men reporting both dysfunctions were also more likely to report smoking, lower urinary tract symptoms, and had greater odds of androgen deficiency than men with no sexual dysfunction. Men with longstanding T1D suffer from an increased burden of OD. Psychogenic factors predominate in men reporting OD only while men who present with concomitant ED report increased burden of diabetes severity, characteristics previously observed with incident ED. ED may be the central impediment to sexual function in men with OD and ED. Longitudinal studies to characterize OD and ED experience over time are warranted.

Quantifying the polygenic contribution to variable expressivity in eleven rare genetic disorders

Rare genetic disorders (RGDs) often exhibit significant clinical variability among affected individuals, a disease characteristic termed variable expressivity. Recently, the aggregate effect of common variation, quantified as polygenic scores (PGSs), has emerged as an effective tool for predictions of disease risk and trait variation in the general population. Here, we measure the effect of PGSs on 11 RGDs including four sex-chromosome aneuploidies (47,XXX; 47,XXY; 47,XYY; 45,X) that affect height; two copy-number variant (CNV) disorders (16p11.2 deletions and duplications) and a Mendelian disease (melanocortin 4 receptor deficiency (MC4R)) that affect BMI; and two Mendelian diseases affecting cholesterol: familial hypercholesterolemia (FH; LDLR and APOB) and familial hypobetalipoproteinemia (FHBL; PCSK9 and APOB). Our results demonstrate that common, polygenic factors of relevant complex traits frequently contribute to variable expressivity of RGDs and that PGSs may be a useful metric for predicting clinical severity in affected individuals and for risk stratification.

Prevalence of and Risk Factors for Diabetic Peripheral Neuropathy in Youth With Type 1 and Type 2 Diabetes: SEARCH for Diabetes in Youth Study

OBJECTIVE

We assessed the prevalence of and risk factors for diabetic peripheral neuropathy (DPN) in youth with type 1 diabetes (T1D) and type 2 diabetes (T2D) enrolled in the SEARCH for Diabetes in Youth (SEARCH) study.

RESEARCH DESIGN AND METHODS

The Michigan Neuropathy Screening Instrument (MNSI) was used to assess DPN in 1,734 youth with T1D (mean ± SD age 18 ± 4 years, T1D duration 7.2 ± 1.2 years, and HbA_1c 9.1 ± 1.9%) and 258 youth with T2D (age 22 ± 3.5 years, T2D duration 7.9 ± 2 years, and HbA_1c 9.4 ± 2.3%) who were enrolled in the SEARCH study and had ≥5 years of diabetes duration. DPN was defined as an MNSI exam score of >2. Glycemic control over time was estimated as area under the curve for HbA_1c.

RESULTS

The prevalence of DPN was 7% in youth with T1D and 22% in youth with T2D. Risk factors for DPN in youth with T1D were older age, longer diabetes duration, smoking, increased diastolic blood pressure, obesity, increased LDL cholesterol and triglycerides, and lower HDL cholesterol (HDL-c). In youth with T2D, risk factors were older age, male sex, longer diabetes duration, smoking, and lower HDL-c. Glycemic control over time was worse among those with DPN compared with those without for youth with T1D (odds ratio 1.53 [95% CI 1.24; 1.88]) but not for youth with T2D (1.05 [0.7; 1.56]).

CONCLUSIONS

The high rates of DPN among youth with diabetes are a cause of concern and suggest a need for early screening and better risk factor management. Interventions in youth that address poor glycemic control and dyslipidemia may prevent or delay debilitating neuropathic complications.

Cardiovascular Autonomic Neuropathy, Sexual Dysfunction, and Urinary Incontinence in Women With Type 1 Diabetes

OBJECTIVE

This study evaluated associations among cardiovascular autonomic neuropathy (CAN), female sexual dysfunction (FSD), and urinary incontinence (UI) in women with type I diabetes mellitus (T1DM).

RESEARCH DESIGN AND METHODS

We studied 580 women with T1DM in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Study (DCCT/EDIC). CAN was defined as: 1) R-R variation <15 with deep breathing or 2) R-R variation of 15-19.9 plus Valsalva ratio ≤1.5 or a supine-to-standing drop of 10 mmHg in diastolic blood pressure. A Sandvik Severity Index of 3-12 defined UI, and a Female Sexual Function Index (FSFI-R) score ≥22.75 defined FSD. Multivariable models estimated associations among CAN, FSD, and UI.

RESULTS

At EDIC year 17, FSD was observed in 41% of women and UI in 30%. No statistically significant associations were observed between measures of CAN at DCCT closeout and subsequent report of FSD or UI. At EDIC year 16/17, there was a 53% increased odds of having UI with a Valsalva ratio ≤1.5. At both EDIC year 13/14 and EDIC year 16/17, a 5-unit increase in R-R variation was associated with a 1.11 greater odds of having FSD.

CONCLUSIONS

In women with T1DM in the DCCT/EDIC, we found significant increased odds of FSD and UI with specific measures of CAN. In long-standing T1DM, CAN may predict development of FSD and may be a useful surrogate for generalized diabetic autonomic neuropathy.

Cardiovascular autonomic neuropathy associates with nephropathy lesions in American Indians with type 2 diabetes

AIMS

Cardiovascular autonomic neuropathy (CAN) predicts clinical diabetic nephropathy (DN). We investigated the relationship between DN structural lesions and CAN.

METHODS

Sixty three Pima Indians with type 2 diabetes underwent kidney biopsies following a 6-year clinical trial testing the renoprotective efficacy of losartan vs. placebo. CAN was assessed a median 9.2years later. CAN variables included expiration/inspiration ratio (E/I), standard deviation of the normal R-R interval (sdNN), and low and high frequency signal power and their ratio (LF, HF, LF/HF); lower values reflect more severe neuropathy. Associations of CAN with renal structural variables were assessed by linear regression adjusted for age, sex, diabetes duration, blood pressure, HbA1c, glomerular filtration rate, and treatment assignment during the trial.

RESULTS

Global glomerular sclerosis was negatively associated with sdNN (partial r=-0.35, p=0.01) and LF (r=-0.32, p=0.02); glomerular basement membrane width was negatively associated with all measures of CAN except for LF/HF (r=-0.28 to -0.42, p<0.05); filtration surface density was positively associated with sdNN, LF, and HF (r=0.31 to 0.38, p<0.05); and cortical interstitial fractional volume was negatively associated with HF (r=-0.27, p=0.04).

CONCLUSIONS

CAN associates with DN lesions.

Effects of exenatide on measures of diabetic neuropathy in subjects with type 2 diabetes: results from an 18-month proof-of-concept open-label randomized study

OBJECTIVE

Experimental studies have reported potential benefit of glucagon-like peptide-1(GLP-1) receptor agonists in preventing diabetic peripheral neuropathy (DPN). We therefore performed a proof-of-concept pilot study to evaluate the effect of exenatide, a GLP-1 agonist, on measures of DPN and cardiovascular autonomic neuropathy (CAN) in patients with type 2 diabetes (T2D).

RESEARCH DESIGN AND METHODS

Forty-six T2D subjects (age 54±10years, diabetes duration 8±5years, HbA1c 8.2±1.3%) with mild to moderate DPN at baseline were randomized to receive either twice daily exenatide (n=22) or daily insulin glargine (n=24). The subjects, with similar HbA1c levels, were followed for 18months. The primary end point was the prevalence of confirmed clinical neuropathy (CCN). Changes in measures of CAN, other measures of small fiber neuropathy such as intra-epidermal nerve fiber density (IENFD), and quality of life were also analyzed.

RESULTS

Glucose control was similar in both groups during the study. There were no statistically significant treatment group differences in the prevalence of CCN, IENFD, measures of CAN, nerve conductions studies, or quality of life indices.

CONCLUSIONS

In this pilot study of patients with T2D and mild to moderate DPN, 18months of exenatide treatment had no significant effect on measures of neuropathy compared with glargine treatment.

Cardiovascular autonomic neuropathy, erectile dysfunction and lower urinary tract symptoms in men with type 1 diabetes: findings from the DCCT/EDIC

PURPOSE

We evaluated the association between cardiovascular autonomic neuropathy, and erectile dysfunction and lower urinary tract symptoms in men with type 1 diabetes.

MATERIALS AND METHODS

Male type 1 diabetes participants (635) in the DCCT/EDIC were studied. Cardiovascular autonomic neuropathy was assessed by standardized cardiovascular reflex tests including changes in respiratory rate variation with deep breathing, Valsalva maneuver (Valsalva ratio) and changes in supine to standing diastolic blood pressure. Erectile dysfunction was assessed by a proxy item from the International Index of Erectile Function, and lower urinary tract symptoms were assessed with the AUASI (American Urological Association Symptom Index). Multivariable logistic regression models estimated the association between cardiovascular autonomic neuropathy and erectile dysfunction and/or lower urinary tract symptoms, adjusting for time weighted glycemic control, blood pressure, age and other covariates.

RESULTS

Men in whom erectile dysfunction and/or lower urinary tract symptoms developed during EDIC had a significantly lower respiratory rate variation and Valsalva ratio at DCCT closeout and EDIC year 16/17 compared to those without erectile dysfunction or lower urinary tract symptoms. In adjusted analysis, participants with cardiovascular autonomic neuropathy had 2.65 greater odds of erectile dysfunction and lower urinary tract symptoms (95% CI 1.47-4.79).

CONCLUSIONS

These data suggest that cardiovascular autonomic neuropathy predicts the development of urological complications in men with long-standing type 1 diabetes. Studies evaluating the mechanisms contributing to these interactions are warranted for targeting effective prevention or treatment.

Neuropathy and related findings in the diabetes control and complications trial/epidemiology of diabetes interventions and complications study

OBJECTIVE To describe the development and progression of neuropathy and related findings among patients with type 1 diabetes who participated in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study. RESEARCH DESIGN AND METHODS The main diabetic peripheral neuropathy (DPN) outcome was assessed using clinical symptoms, signs, and nerve conduction study results during DCCT and repeated in EDIC year 13/14. Cardiovascular autonomic neuropathy (CAN) was assessed by R-R response to paced breathing, Valsalva ratio, and blood pressure response to standing during DCCT and in EDIC years 13/14 and 16/17. Additionally, symptoms reflecting neuropathic pain and autonomic function (including hypoglycemia awareness) were collected yearly in EDIC using standardized questionnaires; peripheral neuropathy was also assessed annually using the Michigan Neuropathy Screening Instrument. Assessments of genitourinary function were collected at EDIC year 10. RESULTS Intensive therapy during the DCCT significantly reduced the risk of DPN and CAN at DCCT closeout (64% and 45%, respectively, P < 0.01). The prevalence and incidence of DPN and CAN remained significantly lower in the DCCT intensive therapy group compared with the DCCT conventional therapy group through EDIC year 13/14. CONCLUSIONS The persistent effects of prior intensive therapy on neuropathy measures through 14 years of EDIC largely mirror those observed for other diabetes complications. DCCT/EDIC provides important information on the influence of glycemic control, and the clinical course of diabetic neuropathy, and, most important, on how to prevent neuropathy in type 1 diabetes.

Peripheral neuropathy in adolescents and young adults with type 1 and type 2 diabetes from the SEARCH for Diabetes in Youth follow-up cohort: a pilot study

OBJECTIVE

To estimate the prevalence of and risk factors for diabetic peripheral neuropathy (DPN) in a pilot study among youth participating in the SEARCH for Diabetes in Youth study.

RESEARCH DESIGN AND METHODS

DPN was assessed using the Michigan Neuropathy Screening Instrument (MNSI) (examination for foot abnormalities, distal vibration perception, and ankle reflexes). An MNSI exam (MNSIE) score >2 is diagnostic for DPN.

RESULTS

The MNSIE was completed in 399 subjects, including 329 youth with type 1 diabetes (mean age 15.7 ± 4.3 years, duration 6.2 ± 0.9 years) and 70 with type 2 diabetes (mean age 21.6 ± 4.1 years, duration 7.6 ± 1.8 years). Glycated hemoglobin (A1C) was similar in both groups (8.8 ± 1.8% for type 1 vs. 8.5 ± 2.9% for type 2). The prevalence of DPN was significantly higher in youth with type 2 compared with those with type 1 diabetes (25.7 vs. 8.2%; P < 0.0001). In unadjusted analyses, diabetes type, older age, longer duration of diabetes, increased waist circumference, elevated blood pressure, lower HDL cholesterol, and presence of microalbuminuria (urinary albumin-to-creatinine ratio >30 mg/g) were associated with DPN. The association between diabetes type and DPN remained significant after adjustment for age and sex (odds ratio 2.29 [95% CI 1.05-5.02], P = 0.03).

CONCLUSIONS

DPN prevalence among youth with type 2 diabetes approached rates reported in adult populations with diabetes. Our findings suggest not only that youth with diabetes are at risk for DPN but also that many already show measurable signs of DPN.

Using large clinical data sets to infer pathogenicity for rare copy number variants in autism cohorts

Copy number variants (CNVs) have a major role in the etiology of autism spectrum disorders (ASD), and several of these have reached statistical significance in case-control analyses. Nevertheless, current ASD cohorts are not large enough to detect very rare CNVs that may be causative or contributory (that is, risk alleles). Here, we use a tiered approach, in which clinically significant CNVs are first identified in large clinical cohorts of neurodevelopmental disorders (including but not specific to ASD), after which these CNVs are then systematically identified within well-characterized ASD cohorts. We focused our initial analysis on 48 recurrent CNVs (segmental duplication-mediated 'hotspots') from 24 loci in 31 516 published clinical cases with neurodevelopmental disorders and 13 696 published controls, which yielded a total of 19 deletion CNVs and 11 duplication CNVs that reached statistical significance. We then investigated the overlap of these 30 CNVs in a combined sample of 3955 well-characterized ASD cases from three published studies. We identified 73 deleterious recurrent CNVs, including 36 deletions from 11 loci and 37 duplications from seven loci, for a frequency of 1 in 54; had we considered the ASD cohorts alone, only 58 CNVs from eight loci (24 deletions from three loci and 34 duplications from five loci) would have reached statistical significance. In conclusion, until there are sufficiently large ASD research cohorts with enough power to detect very rare causative or contributory CNVs, data from larger clinical cohorts can be used to infer the likely clinical significance of CNVs in ASD.

Birth cohort effects on abdominal obesity in the United States: the Silent Generation, Baby Boomers and Generation X

BACKGROUND

Abdominal obesity predicts a wide range of adverse health outcomes. Over the past several decades, prevalence of abdominal obesity has increased markedly in industrialized countries like the United States No previous analyses, however, have evaluated whether there are birth cohort effects for abdominal obesity. Estimating cohort effects is necessary to forecast future health trends and understand the past population-level trends.

METHODS

This analysis evaluated whether there were birth cohort effects for abdominal obesity for the Silent Generation (born 1925-1945), children of the Great Depression; Baby Boomers (born 1946-1964); or Generation X (born 1965-1980). Cohort effects for prevalence of abdominal obesity were estimated using the median polish method with data collected from the National Health and Nutrition Examination Survey (NHANES) between 1988 and 2008. Respondents were aged 20-74 years.

RESULTS

After taking into account age effects and ubiquitous secular changes, the Silent Generation and Generation X had higher cohort-specific prevalence of abdominal obesity than the Baby Boomers. Effects were more pronounced in women than men.

CONCLUSIONS

This work presents a novel finding: evidence that the birth cohorts of the post-World War II Baby Boom appeared to have uniquely low cohort effects on abdominal obesity. The growing prosperity of the post-World War II US may have exposed the baby-boom generation to lower levels of psychosocial and socioeconomic stress than the previous or subsequent generations. By identifying factors associated with the Baby Boomers' low cohort-specific sensitivity to the obesogenic environment, the obesity prevention community can identify early-life factors that can protect future generations from excess weight gain.

Signatures of cool gas fueling a star-forming galaxy at redshift 2.3

Galaxies are thought to be fed by the continuous accretion of intergalactic gas, but direct observational evidence has been elusive. The accreted gas is expected to orbit about the galaxy's halo, delivering not just fuel for star formation but also angular momentum to the galaxy, leading to distinct kinematic signatures. We report observations showing these distinct signatures near a typical distant star-forming galaxy, where the gas is detected using a background quasar passing 26 kiloparsecs from the host. Our observations indicate that gas accretion plays a major role in galaxy growth because the estimated accretion rate is comparable to the star-formation rate.

Birth cohort effects among US-born adults born in the 1980s: foreshadowing future trends in US obesity prevalence

BACKGROUND

Obesity prevalence stabilized in the US in the first decade of the 2000s. However, obesity prevalence may resume increasing if younger generations are more sensitive to the obesogenic environment than older generations.

METHODS

We estimated cohort effects for obesity prevalence among young adults born in the 1980s. Using data collected from the National Health and Nutrition Examination Survey between 1971 and 2008, we calculated obesity for respondents aged between 2 and 74 years. We used the median polish approach to estimate smoothed age and period trends; residual non-linear deviations from age and period trends were regressed on cohort indicator variables to estimate birth cohort effects.

RESULTS

After taking into account age effects and ubiquitous secular changes, cohorts born in the 1980s had increased propensity to obesity versus those born in the late 1960s. The cohort effects were 1.18 (95% CI: 1.01, 1.07) and 1.21 (95% CI: 1.02, 1.09) for the 1979-1983 and 1984-1988 birth cohorts, respectively. The effects were especially pronounced in Black males and females but appeared absent in White males.

CONCLUSIONS

Our results indicate a generational divergence of obesity prevalence. Even if age-specific obesity prevalence stabilizes in those born before the 1980s, age-specific prevalence may continue to rise in the 1980s cohorts, culminating in record-high obesity prevalence as this generation enters its ages of peak obesity prevalence.

Association between cardiovascular autonomic neuropathy and left ventricular dysfunction: DCCT/EDIC study (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications)

OBJECTIVES

The goal of these studies was to determine the association between cardiovascular autonomic neuropathy (CAN) and indices of left ventricle (LV) structure and function in patients with type 1 diabetes (T1DM) in the DCCT/EDIC (Diabetes Control and Complications Trial /Epidemiology of Diabetes Interventions and Complications) study.

BACKGROUND

The pathophysiology of LV dysfunction in T1DM remains unclear, especially when the LV ejection fraction (EF) is preserved. Whether CAN is associated with LV dysfunction is unclear.

METHODS

Indices of LV structure and function were obtained by cardiac magnetic resonance imaging (CMRI). CAN was assessed by cardiovascular reflex testing (R-R response to paced breathing, Valsalva ratio, and blood pressure response to standing). Analyses were performed in 966 DCCT/EDIC participants with valid CMRI and CAN data (mean age 51 years, 52% men, mean diabetes duration 29 years, and mean glycosylated hemoglobin 7.9%).

RESULTS

Systolic function (EF, end-systolic and end-diastolic volumes, stroke volumes) was not different in 371 subjects with CAN compared with 595 subjects without CAN. In multiple-adjusted analyses, participants with either abnormal R-R variation or a composite of abnormal R-R variation, abnormal Valsalva ratio, and postural blood pressure changes had significantly higher LV mass, mass-to-volume-ratio, and cardiac output compared with those with normal tests (p < 0.0001 for all). After further adjustment for traditional cardiovascular risk factors, subjects with abnormal R-R variation had higher LV mass and cardiac output compared with those with a normal R-R variation (p < 0.05).

CONCLUSIONS

In this large cohort of patients with T1DM, CAN is associated with increased LV mass and concentric remodeling as assessed by CMRI independent of age, sex, and other factors. (Diabetes Control and Complications Trial [DCCT]; NCT00360815) (Epidemiology of Diabetes Interventions and Complications [EDIC]; NCT00360893).

Use of the Michigan Neuropathy Screening Instrument as a measure of distal symmetrical peripheral neuropathy in Type 1 diabetes: results from the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications

AIMS

The Michigan Neuropathy Screening Instrument (MNSI) is used to assess distal symmetrical peripheral neuropathy in diabetes. It includes two separate assessments: a 15-item self-administered questionnaire and a lower extremity examination that includes inspection and assessment of vibratory sensation and ankle reflexes. The purpose of this study was to evaluate the performance of the MNSI in detecting distal symmetrical peripheral neuropathy in patients with Type 1 diabetes and to develop new scoring algorithms.

METHODS

The MNSI was performed by trained personnel at each of the 28 Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications clinical sites. Neurologic examinations and nerve conduction studies were performed during the same year. Confirmed clinical neuropathy was defined by symptoms and signs of distal symmetrical peripheral neuropathy based on the examination of a neurologist and abnormal nerve conduction findings in ≥ 2 anatomically distinct nerves among the sural, peroneal and median nerves.

RESULTS

We studied 1184 subjects with Type 1 diabetes. Mean age was 47 years and duration of diabetes was 26 years. Thirty per cent of participants had confirmed clinical neuropathy, 18% had ≥ 4 and 5% had ≥ 7 abnormal responses on the MNSI questionnaire, and 33% had abnormal scores (≥ 2.5) on the MNSI examination. New scoring algorithms were developed and cut points defined to improve the performance of the MNSI questionnaire, examination and the combination of the two.

CONCLUSIONS

Altering the cut point to define an abnormal test from ≥ 7 abnormal to ≥ 4 abnormal items improves the performance of the MNSI questionnaire. The MNSI is a simple, non-invasive and valid measure of distal symmetrical peripheral neuropathy in Type 1 diabetes.

Towards an evidence-based process for the clinical interpretation of copy number variation

The evidence-based review (EBR) process has been widely used to develop standards for medical decision-making and to explore complex clinical questions. This approach can be applied to genetic tests, such as chromosomal microarrays, in order to assist in the clinical interpretation of certain copy number variants (CNVs), particularly those that are rare, and guide array design for optimal clinical utility. To address these issues, the International Standards for Cytogenomic Arrays Consortium has established an EBR Work Group charged with building a framework to systematically assess the potential clinical relevance of CNVs throughout the genome. This group has developed a rating system enumerating the evidence supporting or refuting dosage sensitivity for individual genes and regions that considers the following criteria: number of causative mutations reported; patterns of inheritance; consistency of phenotype; evidence from large-scale case-control studies; mutational mechanisms; data from public genome variation databases; and expert consensus opinion. The system is designed to be dynamic in nature, with regions being reevaluated periodically to incorporate emerging evidence. The evidence collected will be displayed within a publically available database, and can be used in part to inform clinical laboratory CNV interpretations as well as to guide array design.

The impact of continuous subcutaneous insulin infusion and multiple daily injections of insulin on glucose variability in older adults with type 2 diabetes

AIMS

To determine whether continuous subcutaneous insulin infusion (CSII) or multiple daily injections of insulin (MDI) are associated with improved glycemic variability.

METHODS

Type 2 diabetic patients ≥60 years of age were randomized to 12 months of CSII (n=53) or MDI (n=54) therapy. Patients were asked to complete monthly eight-point self-monitored glucose profiles (n=78) and continuous glucose monitoring systems (CGMS) for up to 72 h at Months 0, 6, and 12 (n=77). Within-day mean glucose, standard deviation (SD), range, pre- and post-prandial glucose, M value, and mean amplitude of glycemic excursions (MAGE) were calculated from eight-point profiles. Mean glucose, SD, range, area under the curve (AUC) high (>180 mg/dl) and AUC-low (<70 mg/dl) were calculated from CGMS. Mixed model analyses of variance were used to examine the associations between treatment, time, and the study outcomes, adjusting for any effects of sex.

RESULTS

With the use of the eight-point profiles, CSII and MDI groups did not differ with respect to mean glucose, mean pre-prandial and post-prandial glucose, SD, range, M value, or MAGE. With the CGMS data, there were no significant between-group differences in measures of mean glucose, range, SD, AUC-high, or AUC-low. In both treatment groups, all measures improved over time (P<.0001) except for AUC-low (P=.68) which did not change. There were treatment-by-time interactions when considering the CGMS range (P=.04) and AUC-high (P=.001), but no significant differences were found at individual time points.

CONCLUSIONS

Glucose variability improved equally with CSII and MDI treatment in older patients with type 2 diabetes.

Vibration perception threshold as a measure of distal symmetrical peripheral neuropathy in type 1 diabetes: results from the DCCT/EDIC study

OBJECTIVE

To describe the sensitivity, specificity, positive predictive value, and negative predictive value of vibration perception threshold (VPT) testing in subjects with type 1 diabetes relative to gold standard assessments of peripheral neuropathy.

RESEARCH DESIGN AND METHODS

VPT was determined in 1,177 adults with type 1 diabetes 13-14 years after participating in a study of intensive (INT) versus conventional (CONV) diabetes treatment. Abnormal VPT was defined by values exceeding 2.5 SD above age-specific normal values. Signs and symptoms of peripheral neuropathy were assessed and electrodiagnostic studies were performed to establish definite clinical neuropathy, abnormal nerve conduction, and confirmed clinical neuropathy (the presence of both definite clinical neuropathy and abnormal nerve conduction).

RESULTS

Thirty-seven percent of subjects had definite clinical neuropathy, 61% had abnormal nerve conduction, and 30% had confirmed clinical neuropathy. Abnormal VPT was more common among former CONV than among INT subjects (64 vs. 57%, P < 0.05) and was associated with older age. VPT was a sensitive measure of confirmed clinical neuropathy (87%) and of definite clinical neuropathy (80%) and a specific measure of abnormal nerve conduction (62%). Higher VPT cut points improved test sensitivity and lower cut points improved specificity. Areas under the receiver operating characteristic curves ranged from 0.71-0.83 and were higher for older than for younger subjects and highest for those with confirmed clinical neuropathy.

CONCLUSIONS

VPT was a sensitive measure of peripheral neuropathy. Future researchers may choose to select VPT cut points for defining abnormality based on the population studied and clinical outcome of interest.

DCCT and EDIC studies in type 1 diabetes: lessons for diabetic neuropathy regarding metabolic memory and natural history

The DCCT/EDIC (Diabetes Control and Complications Trial/ Epidemiology of Diabetes Interventions and Complications) provides a comprehensive characterization of the natural history of diabetic neuropathy in patients with type 1 diabetes and provides insight into the impact of intensive insulin therapy in disease progression. The lessons learned about the natural history of distal symmetrical polyneuropathy and cardiovascular autonomic neuropathy and the impact of glycemic control on neuropathy are discussed in this review.

Effect of prior intensive insulin treatment during the Diabetes Control and Complications Trial (DCCT) on peripheral neuropathy in type 1 diabetes during the Epidemiology of Diabetes Interventions and Complications (EDIC) Study

OBJECTIVE

To evaluate the impact of former intensive versus conventional insulin treatment on neuropathy in Diabetes Control and Complications Trial (DCCT) intensive and conventional treatment subjects with type 1 diabetes 13-14 years after DCCT closeout, during which time the two groups had achieved similar A1C levels.

RESEARCH DESIGN AND METHODS

Clinical and nerve conduction studies (NCSs) performed during the DCCT were repeated during the Epidemiology of Diabetes Interventions and Complications (EDIC) study by examiners masked to treatment status on 603 former intensive and 583 former conventional treatment subjects. Clinical neuropathy was defined by symptoms, sensory signs, or reflex changes consistent with distal polyneuropathy and confirmed with NCS abnormalities involving two or more nerves among the median, peroneal, and sural nerves.

RESULTS

The prevalence of neuropathy increased 13-14 years after DCCT closeout from 9 to 25% in former intensive and from 17 to 35% in former conventional treatment groups, but the difference between groups remained significant (P < 0.001), and the incidence of neuropathy remained lower among former intensive (22%) than former conventional (28%) treatment subjects (P = 0.0125). Analytic models of incident neuropathy that adjusted for differences in NCS results at DCCT closeout showed no significant risk reduction associated with former intensive treatment during follow-up (odds ratio 1.17 [95% CI 0.84-1.63]). However, a significant persistent treatment group effect was observed for several NCS measures. Longitudinal analyses of overall glycemic control showed a significant association between mean A1C and measures of incident and prevalent neuropathy.

CONCLUSIONS

The benefits of former intensive insulin treatment persisted for 13-14 years after DCCT closeout and provide evidence of a durable effect of prior intensive treatment on neuropathy.

The AsTex: clinimetric properties of a new tool for evaluating hand sensation following stroke

OBJECTIVES

To investigate the clinimetric properties and clinical utility of the AsTex((R)), a new clinical tool for evaluation of hand sensation following stroke.

DESIGN

The AsTex((R)) was administered on two occasions separated by a week to appraise test-retest reliability, and by three assessors on single occasion to establish inter-rater reliability. Pilot normative values were collected in an age-stratified sample. Clinical utility was evaluated based on ease of administration, ceiling and floor effects, and responsiveness to sensory recovery.

PARTICIPANTS

Test-retest (n = 31) and inter-rater (n = 31) reliability and normative values (n = 95) for the AsTex((R)) were established in neurologically normal participants aged 18-85 years. Test-retest reliability was investigated in 22 individuals a mean of 46 months (range 12-125) post stroke and clinical utility was evaluated in an additional 24 subacute stroke participants a mean of 29.4 days (range 12-41) post stroke.

MAIN MEASURE

The AsTex((R)).

RESULTS

The AsTex((R)) demonstrated excellent test-retest (intraclass correlation coefficient (ICC) = 0.98, 95% confidence interval (95% CI) = 0.97-0.99) and inter-rater reliability (ICC = 0.81, 95% CI = 0.73-0.87) in neurologically normal participants. Test-retest reliability of the AsTex((R)) in individuals following stroke was excellent (ICC = 0.86, 95% CI = 0.68-0.94). The AsTex((R)) was simple to administer, demonstrated small standard error of measurement (0.14 mm), minimal floor and ceiling effects (12.5% and 8.3%) and excellent responsiveness (standardized response mean = 0.57) in subacute stroke participants.

CONCLUSION

The AsTex((R)) is a reliable, clinically useful and responsive tool for evaluating hand sensation following stroke.

Effects of prior intensive insulin therapy on cardiac autonomic nervous system function in type 1 diabetes mellitus: the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications study (DCCT/EDIC)

BACKGROUND

The Epidemiology of Diabetes Interventions and Complications (EDIC) study, a prospective observational follow-up of the Diabetes Control and Complications Trial (DCCT) cohort, reported persistent benefit of prior intensive therapy on retinopathy and nephropathy in type 1 diabetes mellitus. We evaluated the effects of prior intensive insulin therapy on the prevalence and incidence of cardiac autonomic neuropathy (CAN) in former DCCT intensive and conventional therapy subjects 13 to 14 years after DCCT closeout.

METHODS AND RESULTS

DCCT autonomic measures (R-R variation with paced breathing, Valsalva ratio, postural blood pressure changes, and autonomic symptoms) were repeated in 1226 EDIC subjects in EDIC year 13/14. Logistic regression models were used to calculate the odds of incident CAN by DCCT treatment group after adjustment for DCCT baseline covariates, duration in the DCCT, and quantitative autonomic measures at DCCT closeout. In EDIC year 13/14, the prevalence of CAN using the DCCT composite definition was significantly lower in the former intensive group versus the former conventional group (28.9% versus 35.2%; P=0.018). Adjusted R-R variation was significantly greater in the former DCCT intensive versus the former conventional group (29.9 versus 25.9; P<0.001). Prior DCCT intensive therapy reduced the risks of incident CAN by 31% (odds ratio, 0.69; 95% confidence interval, 0.51 to 0.93) and of incident abnormal R-R variation by 30% (odds ratio, 0.70; 95% confidence interval, 0.51 to 0.96) in EDIC year 13/14.

CONCLUSIONS

Although CAN prevalence increased in both groups, the incidence was significantly lower in the former intensive group compared with the former conventional group. The benefits of former intensive therapy extend to measures of CAN up to 14 years after DCCT closeout.

U-type exchange is the most frequent mechanism for inverted duplication with terminal deletion rearrangements

BACKGROUND

Chromosomal rearrangements resulting in an interstitial inverted duplication with concomitant terminal deletion were first described for the short arm of chromosome 8 in 1976. Since then, this type of alteration has been identified and characterised for most chromosome arms. Three mechanisms are commonly proposed to explain the origin of this type of rearrangement. All three mechanisms involve formation of a dicentric chromosome that then breaks in a subsequent meiotic division to produce a monocentric duplicated and deleted chromosome. However, the events leading to the formation of the dicentric chromosome differ between the mechanisms. In one mechanism, either parent carries a paracentric inversion. This results in formation of a loop during meiotic pairing with a recombination event occurring in the loop. In the second mechanism, inverted low copy repeats in the same chromosome arm allow partial folding of one homologue onto itself with a recombination event between the inverted repeats. The third mechanism involves a pre-meiotic double-strand break with subsequent fusion, or U-type exchange, between the sister chromatids. The first two mechanisms require a single copy region to exist between the duplicated and deleted regions on the derivative chromosome, and therefore high resolution analysis of the rearrangement can be used to distinguish between these mechanisms.

METHODS AND RESULTS

Using G-banded chromosome analysis, fluorescence in situ hybridisation (FISH) and array comparative genomic hybridisation (CGH), we describe 17 new cases of inverted duplication with terminal deletion of 2q, 4p, 5p, 6q, 8p, 9p, 10q, 13q, 15q, 18p, 18q, and 22q.

CONCLUSIONS

These new cases, combined with previously described cases, demonstrate that U-type exchange is the most frequent mechanism for this rearrangement and can be observed on most, or perhaps all, chromosome arms.

Effectiveness of physiotherapy for adults with cerebellar dysfunction: a systematic review

Objective: To systematically review the literature investigating the effectiveness of physiotherapy in adults with cerebellar dysfunction and to document treatment strategies currently employed in the physiotherapy management of this patient population.

Data sources: Eight electronic databases were searched to source English-language studies published up to December 2007. Secondary searching of reference lists was also undertaken.

Review methods: Studies were included if they used a quantitative research design to investigate the effect of physiotherapy on adults with diagnosed cerebellar dysfunction. Three reviewers were involved in study selection. Eligible studies were assessed for methodological quality. Data pertaining to the participants, interventions received, outcomes measured, and the effectiveness of the intervention were systematically extracted and synthesised in a narrative format.

Results: Nine studies were included in the review. The majority of the studies (n = 7) were case studies or case series. The median quality score was 8/16 (range 4—10). The studies were heterogeneous in terms of patient characteristics, interventions received and outcomes measured. All studies reported positive effects of physiotherapy over a range of outcomes measured, in particular balance, gait and function.

Conclusion: There is some evidence that supports the effectiveness of physiotherapy in adults with cerebellar dysfunction. However, these results need to be interpreted with caution due to the low volume, quality and clinical applicability of this evidence. There is a need for further high-quality research in this area.

Beyond Glycemic Control

The improved understanding of glucoregulatory hor- mones has driven the development of new pharmacologic agents to treat type 2 diabetes. One new class of antihy- perglycemic medication is incretin mimetics (IMs). Incretin hormones potentiate insulin secretion following meal ingestion, a process that is impaired in patients with type 2 diabetes. GLP-1, a 30–amino acid peptide incretin hormone, is produced in the L cells of the ileum and colon. Studies have shown that a 6-week continuous GLP-1 infusion in patients with type 2 diabetes improved glycemic control and β-cell function and delayed gastric emptying. Despite the rapid degradation and inactivation of GLP-1 by the enzyme dipeptidyl peptidase IV (DPP- IV), agents that mimic the actions of GLP-1 are of great clinical interest. First-in-class IM exenatide, a GLP-1 receptor agonist resistant to DPP-IV inactivation, mimics many beneficial glucoregulatory effects of GLP-1, such as suppressing glucagon secretion, regulating gastric emptying and satiety, and increasing glucose-dependent insulin secretion. Exenatide is an adjunctive therapy for patients who take metformin, a sulfonylurea, a thiazo- lidinedione, or a combination of these oral medications but have not achieved glycemic control. An 82-week, open-label extension trial has shown that exenatide is well tolerated and that the benefits, including improved glycemic control, weight loss, and mitigation of cardio- vascular risk factors, are sustained.

Influence of adhesion and friction on the geometry of packings of spherical particles

We study the effect of both adhesion and friction on the geometry of monosized packings of spheres by means of discrete element simulations. We use elastic properties that are characteristic of materials typically used for particulate processing (Young's modulus in the range 20-200 GPa). The geometrical features, both global and local, of the packings are studied using a variety of approaches in order to investigate their ability to quantify the effect of adhesion and/or friction. We show that both adhesion and friction interaction decrease the packing fraction. The very localized ordering that adhesion triggers is particularly investigated by use of the radial distribution function, the ordering parameter Q(6) , and four triclinic cells that allow a description of the microstructure at the local level. We show that the probability of occurrence of these triclinic cells is approximately proportional to their degree of freedom when neither adhesion nor friction plays a role. We find that the introduction of adhesive interactions increases the probability of occurrence of those cells that have the lowest degree of freedom.

Subclinical neuropathy among Diabetes Control and Complications Trial participants without diagnosable neuropathy at trial completion: possible predictors of incident neuropathy?

OBJECTIVE

We sought to evaluate the prevalence of subclinical neuropathy in intensive and conventional treatment groups at completion of the Diabetes Control and Complications Trial (DCCT).

RESEARCH DESIGN AND METHODS

We assessed neuropathy using nerve conduction results obtained at DCCT completion after stratifying the DCCT cohort to exclude subjects with progressively less severe degrees of diagnosable neuropathy. We began with those who had confirmed clinical neuropathy (the primary DCCT end point) and eventually excluded all subjects with any clinical or electrodiagnostic evidence of neuropathy.

RESULTS

After excluding subjects with confirmed clinical neuropathy at DCCT completion, 8 of 10 nerve conduction measures (including all lower-extremity measures) were significantly improved in the intensive treatment group (O'Brien rank-sum test across all nerve conduction measures, P < 0.0001). Conduction velocity group differences were substantial, and the peroneal conduction velocity averaged 3.1 m/s faster in the intensive compared with the conventional treatment group (45.1 vs. 42.0 m/s, P < 0.0001). Numerous significant differences in median and peroneal motor conduction velocities favoring the intensive treatment group persisted, regardless of the exclusion criteria applied.

CONCLUSIONS

Intensive and conventional treatment group subjects without diagnosable neuropathy at DCCT completion had significant differences in electrophysiologic measurements favoring the intensive treatment group. Differences in subsequent incident neuropathy between the original treatment groups may reflect, in part, their levels of subclinical neuropathy at DCCT completion, rather than persistent metabolic effects.

Gait and balance impairment in early multiple sclerosis in the absence of clinical disability

This study evaluated the gait and balance performance of two clinically distinct groups of recently diagnosed and minimally impaired multiple sclerosis (MS) patients (Expanded Disability Status Scale range 0-2.5), compared to control subjects. Ten MS patients with mild pyramidal signs (Pyramidal Functional Systems 1.0), 10 MS patients with no pyramidal signs (Pyramidal Functional Systems 0) and 20 age- and gender-matched control subjects were assessed using laboratory-based gait analysis and clinical balance measures. Both MS groups demonstrated reduced speed and stride length (P < 0.001), and prolonged double limb support (P <0.02), compared to the control group, along with alterations in the timing of ankle muscle activity, and the pattern of ankle motion during walking, which occurred independent of gait speed. The pyramidal MS group walked with reduced speed (P = 0.03) and stride length (P = 0.04), and prolonged double limb support (P =0.01), compared to the non-pyramidal group. Both MS groups demonstrated concomitant balance impairment, performing poorly on the Functional Reach Test compared to the control group (P <0.05). The identification of incipient gait and balance impairment in MS patients with recent disease onset suggests that motor function may begin to deteriorate in the early stages of the disease, even in the absence of clinical signs of pyramidal dysfunction.

New insights into glucose regulation

This review article describes the regulation of glucose homeostasis in subjects with and without diabetes based on the emergence of new information and discusses modes of action, attributes, and limitations of current diabetes therapies. In normal physiology, glucose homeostasis is tightly controlled by the interaction of pancreatic and gut hormones. Since the 1920s, diabetes has been viewed as a disease caused by deficient secretion of insulin, resulting in reduced glucose uptake and subsequent hyperglycemia. The discovery in the 1950s of the pancreatic hormone glucagon, which opposes insulin by increasing glucose appearance in the circulation, resulted in a bihormonal model of glucose homeostasis. More recently, with the discovery of the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) in the 1970s and the pancreatic hormone amylin in the 1980s, it is now understood that several organs and hormones play roles in maintaining glucose homeostasis. Therapies for diabetes have focused on compensation for deficient insulin action through stimulation of insulin secretion, administration of insulin itself, reduction of peripheral insulin resistance, or decreased glucose absorption from the intestine. The discoveries of amylin and GLP-1 have furthered our understanding of the abnormalities involved in diabetes, enabling the development of additional therapeutic options.

Neuropathy among the diabetes control and complications trial cohort 8 years after trial completion

OBJECTIVE

To evaluate the impact of prior intensive diabetes therapy on neuropathy among former Diabetes Control and Complications Trial (DCCT) participants.

RESEARCH DESIGN AND METHODS

At the conclusion of the DCCT, subjects in the intensive group were encouraged to maintain intensive therapy, and subjects in the conventional group were encouraged to begin intensive therapy. Thereafter, we annually assessed neuropathy as part of the Epidemiology of Diabetes Intervention and Complications (EDIC) study. Neuropathy was defined using the Michigan Neuropathy Screening Instrument (MNSI). We recorded potential adverse consequences of neuropathy.

RESULTS

At the first EDIC examination, 1,257 subjects participated in the neuropathy assessment. Consistent with DCCT results, the former intensive group showed a lower prevalence of neuropathy than the conventional group based on positive questionnaire (1.8 vs. 4.7%; P = 0.003) or examination (17.8 vs. 28.0%; P < 0.0001) results. Despite similar levels of glycemic control, symptoms and signs of neuropathy remained less prevalent among the former intensive group compared with the conventional group. At the beginning of the EDIC study, prior intensive therapy reduced the odds of having symptoms and signs of neuropathy using MNSI criteria by 64% (P = 0.0044) and 45% (P < 0.0001), respectively, with similar odds reductions observed for both neuropathic symptoms (51%, P < 0.0001) and neuropathic signs (43%, P < 0.0001) across 8 years of EDIC follow-up.

CONCLUSIONS

The benefits of 6.5 years of intensive therapy on neuropathy status extended for at least 8 years beyond the end of the DCCT, similar to the findings described for diabetic retinopathy and nephropathy.

Subtelomere FISH analysis of 11 688 cases: an evaluation of the frequency and pattern of subtelomere rearrangements in individuals with developmental disabilities

BACKGROUND

Subtelomere fluorescence in situ hybridisation (FISH) analysis has increasingly been used as an adjunct to routine cytogenetic testing in order to detect small rearrangements. Previous reports have estimated an overall abnormality rate of 6%, with a range of 2-29% because of different inclusion criteria.

METHODS

This study presents data compiled from 11 688 cases referred for subtelomere FISH testing in three clinical cytogenetic laboratories.

RESULTS

In this study population, the detection rate for clinically significant subtelomere abnormalities was approximately 2.5%, with an additional 0.5% detection of presumed familial variants. Approximately half of the clinically significant abnormalities identified were terminal deletions, the majority of which were de novo. Most of the remaining cases were unbalanced translocations between two chromosomes or two arms of the same chromosome. Approximately 60% of the unbalanced translocations were inherited from a parent carrying a balanced form of the rearrangement. Other abnormalities identified included tandem duplications, apparently balanced translocations, partial deletions, and insertions. Interestingly, 9 cases (0.08%) were found to have interstitial deletions of non-telomeric control loci, either BCR on 22q or PML on 15q. The most common clinically significant imbalances found were deletions of 1p, 22q, 4p, 9q, 8p, 2q and 20p. The most common familial variants were a deletion or duplication of 10q, deletion of 4q, deletion of Yq, and duplication of X/Yp onto Xq.

CONCLUSIONS

This study of subtelomere rearrangements is a 20 fold increase in number over the previously reported largest study and represents an unbiased analysis of subtelomere rearrangements in a large, unselected patient population.

Calibration of 6q subtelomere deletions to define genotype/phenotype correlations

Testing for subtelomere abnormalities in patients with idiopathic mental retardation has become a useful diagnostic tool. However, limited data exist regarding genotype/phenotype correlations for specific subtelomere imbalances. We have ascertained five patients with 6q subtelomere deletions either as a result of an isolated deletion or as a result of an unbalanced translocation, and developed a molecular ruler assay utilizing BAC or PAC clones and determined the size of the deleted regions to range from <0.5 to 8 Mb. To establish genotype/phenotype correlations for distal 6q, we compared the clinical features of these patients to previously reported cases of 6q subtelomere and cytogenetically visible deletions and found that they shared multiple abnormalities, suggesting that the causative genes may lie in the region of the smallest 6q subtelomeric deletion, approximately 400 kb from the telomere. However, multiple unique features were present only in patients with cytogenetically visible 6q deletions, indicative that genes involved in the development of these features may lie more proximally on 6q. These initial studies demonstrate the ability to develop genotype/phenotype correlations for subtelomere rearrangements, which will aid in the diagnosis and prognosis of these patients and may help narrow the search for relevant developmental genes.

A clinical trial of continuous subcutaneous insulin infusion versus multiple daily injections in older adults with type 2 diabetes

OBJECTIVE

To compare the efficacy and safety of continuous subcutaneous insulin infusion (CSII) and multiple daily injection (MDI) in older adults with insulin-treated type 2 diabetes and to assess treatment satisfaction and quality of life.

RESEARCH DESIGN AND METHODS

Adults (n = 107) > or =60 years of age (mean age 66 years) with insulin-treated type 2 diabetes (mean duration 16 years, BMI 32 kg/m(2), and HbA(1C) [A1C] 8.2%) were randomized to CSII (using insulin lispro) or MDI (using insulin lispro and insulin glargine) in a two-center, 12-month, prospective, randomized, controlled clinical trial. Efficacy was assessed with A1C, safety by frequency of hypoglycemia, and treatment satisfaction and quality of life with the Diabetes Quality of Life Clinical Trial Questionnaire and the 36-item short-form health survey, version 2.

RESULTS

Forty-eight CSII subjects (91%) and 50 MDI subjects (93%) completed the study. Mean A1C fell by 1.7 +/- 1.0% in the CSII group to 6.6% and by 1.6 +/- 1.2% in the MDI group to 6.4%. The difference in A1C between treatment groups was not statistically significant (P = 0.20). Eighty-one percent of CSII subjects and 90% of MDI subjects experienced at least one episode of minor (self-treated) hypoglycemia (P = 0.17), and three CSII and six MDI subjects experienced severe hypoglycemia (P = 0.49). Rates of severe hypoglycemia were similarly low in the two groups (CSII 0.08 and MDI 0.23 events per person-year, P = 0.61). Weight gain did not differ between groups (P = 0.70). Treatment satisfaction improved significantly with both CSII and MDI (P < 0.0001), and the difference between groups was not statistically significant (P = 0.58).

CONCLUSIONS

In older subjects with insulin-treated type 2 diabetes, both CSII and MDI achieved excellent glycemic control with good safety and patient satisfaction.

Photoreceptor cell dysplasia in two Tippler pigeons

Two 12-week-old Tippler pigeons were evaluated for ocular abnormalities associated with congenital blindness. The pigeons were emaciated and blind. Biomicroscopy and direct and indirect ophthalmoscopy findings of the Tippler pigeons were normal with the exception of partially dilated pupils at rest. Scotopic (blue stimuli) and photopic monocular electroretinograms were extinguished in the blind Tippler pigeons. Histological and electron microscopy studies revealed reduced numbers of rods and cones, and an absence of the double cone complex. The photoreceptor cells' outer segments were absent, and the inner segments were short and broad. The number of cell nuclei in the outer and inner nuclear layers was decreased, and the internal and external plexiform layers were reduced in width. Photoreceptor cell endfeet with developing synaptic ribbons were present in the external plexiform layer. Inflammatory cell and subretinal debris was not seen. The electroretinographic, histopathological, and ultrastructural findings of the blind Tippler pigeons support the diagnosis of a photoreceptor cell dysplasia.

Orexin-immunoreactive inputs to rat sympathetic preganglionic neurons

Orexin increases blood pressure and orexin-immunoreactive (IR) axons robustly innervate the spinal cord. Seeking anatomical evidence for direct effects of orexin on sympathetic preganglionic neurons (SPN), we used immunohistochemistry to study the relationships between orexin-IR axons and SPN identified by immunoreactivity for choline acetyltransferase (ChAT) or for cholera toxin B retrogradely transported from the superior cervical ganglion (SCG). In the intermediolateral cell column (IML), varicose, orexin-positive axons closely apposed almost all SPN in segments T1 and T2, but appositions were rare in T4-L2. Orexin fibers also apposed ChAT-IR cell bodies in the intercalated nucleus and the central autonomic area from T1 to L2. Orexin-IR synapses were identified ultrastructurally on SPN projecting to the SCG. Since SPN involved in cardiovascular control cluster in the IML of mid- and lower thoracic cord, these findings suggest that orexin affects blood pressure by acting on supraspinal neurons rather than SPN.

Improving diabetes processes of care in managed care

OBJECTIVE

To evaluate the impact of systematic patient evaluation and patient and provider feedback on the processes and intermediate outcomes of diabetes care in Independent Practice Association model internal medicine practices.

RESEARCH DESIGN AND METHODS

Nine practices providing care to managed care patients were randomly assigned as intervention or comparison sites. Intervention-site subjects had Annual Diabetes Assessment Program (ADAP) assessments (HbA(1c), blood pressure, lipids, smoking, retinal photos, urine microalbumin, and foot examination) at years 1 and 2. Comparison-site subjects had ADAP assessments at year 2. At Intervention sites, year 1 ADAP results were reviewed with subjects, mailed to providers, and incorporated into electronic medical records with guideline-generated suggestions for treatment and follow-up. Medical records were evaluated for both groups for the year before both the year 1 and year 2 ADAP assessments. Processes and intermediate outcomes were compared using linear and logistic mixed hierarchical models.

RESULTS

Of 284 eligible subjects, 103 of 173 (60%) at the Intervention sites and 71 of 111 (64%) at the comparison sites participated; 83 of 103 (81%) of the intervention-site subjects returned for follow-up at year 2. Performance of the six recommended assessments improved in intervention-site subjects at year 2 compared with year 1 (5.8 vs. 4.3, P = 0.0001) and compared with comparison-site subjects at year 2 (4.2, P = 0.014). No significant changes were noted in intermediate outcomes.

CONCLUSIONS

The ADAP significantly improved processes of care but not intermediate outcomes. Additional interventions are needed to improve intermediate outcomes.